1. Field of Invention
This invention relates to home carbonation devices, especially those that are for simple, inexpensive, small-scale production of carbonated beverages.
2. Description of Prior Art
Current home carbonation techniques include using yeast, dry ice, compressed carbon dioxide, and chemical reactants to obtain the carbon dioxide for carbonating liquids. The current techniques have weaknesses in the area of simplicity and corresponding price, or availability of product, or introduction of undesirable byproducts.
One method for carbonating liquids involves using yeast. In this method, some yeast is added to a sweet sugar-based liquid. The yeast bacteria consume the sugars and produce carbon dioxide as a byproduct. This carbon dioxide production continues for a number of days in a warm environment after which it is to be kept refrigerated. This method is simple, inexpensive, and yeast is fairly easy to come by, but there are several drawbacks to it. First, yeast bacteria need sugar to produce carbon dioxide. This means that one cannot carbonate sugar-free beverages, or water alone. Second, the yeast is placed directly into the beverage to be carbonated. The flavor of the yeast can be unpleasant to taste. Third, yeast bacteria are biological creatures and can be unpredictable. New yeast can be healthy and produce larger amounts of carbon dioxide than old yeast would. Furthermore, yeast thrives better in warm environments, making more carbon dioxide in warm conditions and less in cold conditions. This opposes the fact that carbon dioxide dissolves more readily in cold liquid than in warm. Unexpected variations in temperature or carbon dioxide production times can lead to explosive pressures within the container being used.
Another method for carbonating liquids includes using dry ice as a source of carbon dioxide. In this method, carbon dioxide is in a solid state, and is placed into the liquid to be carbonated. The carbon dioxide sublimates from a solid to gaseous state, and carbonates the liquid. Because the freezing point of carbon dioxide is so low, it will begin the sublimation process under normal atmospheric conditions, even if it is kept in household freezers. This means that one cannot store dry ice at home, and so if it is to be used for carbonation, it will have to be purchased and used on the day of carbonation. The low temperature of dry ice also makes it a hazardous material, introducing the risk of freezing skin. Furthermore, dry ice is not readily available and must be purchased at special outlets. It is inconvenient to use dry ice, because one needs to plan ahead to purchase the dry ice before preparing the beverage. Because of this, the current household method for using dry ice often includes putting the liquid into a large bucket or barrel, and carbonating large quantities of liquid at a time. Making carbonated beverages with dry ice becomes an extensive procedure that exceeds the limits of convenience.
Another source of carbon dioxide used for household carbonation is compressed carbon dioxide. One such design is found in U.S. Pat. No. 6,036,054 issued to Grill Mar. 14, 2000. In this patent, compressed carbon dioxide can be injected into an existing soda-pop bottle, but it involves a valve system which is relatively complicated to manufacture. Systems for injecting compressed carbon dioxide into a liquid are complex. Furthermore, as with dry ice, compressed carbon dioxide is not readily available and must be obtained or recharged at special outlets. Compressed carbon dioxide carbonation systems are relatively complicated and expensive.
Using chemical reactants that produce carbon dioxide is another way to carbonate a beverage. Of the simple devices that use chemical reactants and can be used on a small scale, some do not use common household reactants. These require obtaining the special reactants, or reactants prepared in a special way. There are some that can use common household reactants. U.S. Pat. No. 4,458,584 issued to Annese et al. Jul. 10, 1984 was designed primarily for home use, and used chemical reactants to produce the carbon dioxide. It uses a specially designed container and a sophisticated lid and reaction system that is not as simple or inexpensive to manufacture as it could be.
Home carbonation devices in general can struggle for market success due in part to the low cost and high availability of soda-pop. The convenience and relatively low price of soda-pop often keeps consumers purchasing soda-pop more often than they make it. Carbonating beverages at home usually holds more of a novel advantage rather than an economical or convenient advantage as a replacement source of soda-pop. Because of this, a home carbonation device should be low enough in cost to justify a novel purchase, rather than as a money-saving or time-saving investment.
Despite the many home carbonation techniques found in prior art, they have not succeeded in being simple in design, easy and inexpensive to manufacture, while utilizing a convenient source of carbon dioxide, and preventing unpleasant byproducts from entering the beverage.